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Hi folks: Because I live at 6500 feet, I'm concerned over the 20% power loss I likely can expect from any new engine. The boat is rated for 40 hp. The Tohatsu is about the lightest I can find. At this altitude, the 40 is about 32 hp and a 50 hp is likely about 40 hp, the rating on the boat. Since the Tohatsu 40 and 50 hp weigh the same, what's the downside to getting a 50 hp? Thanks.
I am helping a whaler owner in Utah who is getting his engine setup for the high altitude, 6600 ft.
Engines loose ~3% of their hp for every 1,000 ft of elevation. A 115 is effectively a 90 at 6600 ft.
Keep in mind that prop selection may be very different given the elevation.
With a WOT of 5850, 1.85 gear ratio, target speed of 32 (based on 40hp), 5% slip, the prop calculator is showing 11" of pitch. In stainless steel, that is part # PT4050P11. http://www.tohatsu.com/accessories/pr.../prop.html
This would be a good place to start. A tach and a gps will be necessary to test props.
I would talk to the dealer about them allowing you to test out a few props.
If you ever take the boat lower, you will need a different prop.
Edit: Corrected target speed, based off 40hp, recalculated pitch, revised part #
Edited by Phil T on 08/20/18 - 7:52 AM
1992 Outrage 17 I
2019 E-TEC 90, Viper 17 2+
2018 Load Rite Elite 18280096VT
